Coulomb gap in a doped semiconductor near the metal-insulator transition: Tunneling experiment and scaling ansatz

1999/02/28 by Mark Lee, J. G. Massey, V. L. Nguyen +3 · 2 citations
Engineering · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Semiconductor materials and devices #cond-mat.dis-nn #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.60.1582

published as Physical Review B 60(3), 1582 (1999) · 10 pages, 7 figures, published in Phys. Rev. B

openalex publication_date 1999/07/15 · arxiv created 2014/11/18 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Electron tunneling experiments are used to probe Coulomb correlation effects in the single-particle density of states (DOS) of boron-doped silicon crystals near the critical density n_c of the metal-insulator transition (MIT). At low energies (\ensuremathε<~0.5 meV), a DOS measurement distinguishes between insulating and metallic samples with densities 10 to 15 % on either side of n_c. However, at higher energies (\ensuremath∼1 meV<~\ensuremathε<~50 meV) the DOS of both insulators and metals show a common behavior, increasing with energy as \ensuremathε^m where m is roughly 0.5. The observed characteristics of the DOS can be understood using a classical treatment of Coulomb interactions combined with a phenomenological scaling ansatz to describe the length-scale dependence of the dielectric constant as the MIT is approached from the insulating side.

Citations

• Continuous Quantum Phase Transitions
• Universal Linear Density of States for Tunneling into the Two-Dimensional Electron Gas in a Magnetic Field
• Coulomb gap and low temperature conductivity of disordered systems
• Scaling Theory of Localization: Absence of Quantum Diffusion in Two Dimensions

Cited by

• Quasiballistic correction to the density of states in three-dimensional metal
• Marginal Stability in Structural, Spin, and Electron Glasses